Radiofrequency ablation of tachyarrhythmias in patients with Ebstein's anomaly

Electocardiographic features in Ebstein's disease

INTRODUCTION

Ebstein's disease (ED) is a rare and heterogeneous congenital heart disease affecting the tricuspid valve and the right ventricle. Few studies have analyzed the electrocardiographic features of this disease.

AIM

To describe the electrocardiographic features observed in Ebstein's disease.

METHODS

We conducted a retrospective descriptive study that enrolled 26 patients followed for ED.

RESULTS

The mean age of discovery of the ME was 103.5±99 months [0-31 years]. The diagnosis of ME is most often made between 5 and 10 years. We noted right atrial hypertrophy in 11 patients (42%), right ventricular hypertrophy in half of the patients. Right axial deviation was noted in 11 patients (42%). Eight patients (30%) had wide QRS≥ 120 ms. Seven of these 8 patients (27%) had a fragmented QRS appearance. A right bandle block was noted in 22 patients (84%), it was a complete block in 7 cases (27%). A preexcitation was found in 6 patients (23%). The localization of accessory pathway was right postero-septal in all cases. Rhythmic disorders were noted in 9 patients (34%). It was a junctional tachycardia in 3 patients (11%), atrial flutter in 4 patients (15%) and atrial fibrillation in 2 patients (7%). A second degree atriventricular block was observed in one patient, it was Mobitz I type. Two cases of postoperative rhythm disturbances were recorded: paroxysmal atrial fibrillation and junctional tachycardia related to Wolf Parkinson White (WPW) syndrome.

CONCLUSION

Surface ECG in the ED is often pathological with prevalence of rhythm disturbances related to WPW syndrome.

Mahaim fibers coexisting with coarctation of aorta and bicuspid aortic valve

We found a coexistence of Mahaim fibers, coarctation of aorta and bicuspid valve in a young patient presenting with palpitations and subraventricular tachycardia. This rare combination of these three congenital cardiac abnormalities occurring in the same patient has not been reported previously. Detailed cardiac studies unmasked the patient's cardiac abnormalities. Furthermore, successful percutaneous intervention in treating coarctation and catheter-based ablation of Mahaim fibers were performed with resolution of symptoms. This case is discussed here in detail, alongside a review of the literature.

Perioperative and Anesthetic Considerations in Ebstein’s Anomaly

Ebstein’s anomaly is a complex and heterogeneous form of congenital heart disease characterized by malformation and apical displacement of the tricuspid valve leaflets. Patients may present at any time from the neonatal period to adulthood with symptoms ranging from cardiac failure and cyanosis to paroxysmal arrhythmias. Depending on the timing of presentation, various surgical options are available for the management of symptomatic patients. This review will discuss the perioperative and anesthetic management of patients with Ebstein’s anomaly with reference to the more common surgical approaches.

Radiofrequency catheter ablation in children with supraventricular tachycardias: intermediate term follow up results

The Purpose of the Study

Radiofrequency (RF) catheter ablation represents an important advance in the management of children with cardiac arrhythmias and has rapidly become the standard and effective line of therapy for supraventricular tachycardias (SVTs) in pediatrics. The purpose of this study was to evaluate the intermediate term follow up results of radiofrequency catheter ablation in treatment of SVT in pediatric age group.

Methods

A total of 60 pediatric patients (mean age = 12.4 ± 5.3 years, ranged from 3 years to 18 years; male: female = 37:23; mean body weight was 32.02 ± 12.3 kg, ranged from 14 kg to 60 kg) with clinically documented SVT underwent an electrophysiologic study (EPS) and RF catheter ablation at Children’s Hospital Mansoura University, Mansoura, Egypt during the period from January 2008 to December 2009 and they were followed up until October 2011.

Results

The arrhythmias included atrioventricular reentrant tachycardia (AVRT; n = 45, 75%), atrioventricular nodal reentrant tachycardia (AVNRT; n = 6, 10%), and atrial tachycardia (AT; n = 9, 15%). The success rate of the RF catheter ablation was 93.3% for AVRT, 66.7% for AVNRT, and 77.8% for AT, respectively. Procedure-related complications were infrequent (7/60, 11.7%), (atrial flutter during RF catheter ablation (4/60, 6.6%); ventricular fibrillation during RF catheter ablation (1/60, 1.6%); transient complete heart block during RF catheter ablation (2/60, 3.3%)). The recurrence rate was 8.3% (5/60) during a follow-up period of 34 ± 12 months.

Conclusion

RF catheter ablation is an effective and safe method to manage children with SVT.

The Results of Radiofrequency Catheter Ablation of Supraventricular Tachycardia in Children

BACKGROUND

Radiofrequency (RF) catheter ablation represents a major advance in the management of children with cardiac arrhythmias and has rapidly become the standard of care for the first-ling therapy of supraventricular tachycardias (SVTs). The purpose of this study was to investigate the results of the RF catheter ablation of SVTs in pediatric patients.

METHODS

From December 1989 to August 2005, a total of 228 pediatric patients (age: 9 +/- 7 years, range: 5-18 years; male:female = 117:111) with clinically documented SVT underwent an electrophysiologic study and RF catheter ablation at our institution.

RESULTS

The arrhythmias included atrioventricular reentrant tachycardia (AVRT; n = 140, 61%), atrioventricular nodal reentrant tachycardia (AVNRT; n = 66, 29%), atrial tachycardia (AT; n = 11, 5%), and atrial flutter (AFL; n = 11, 5%). The success rate of the RF catheter ablation was 92% for AVRT, 97% for AVNRT, 82% for AT, and 91% for AFL, respectively. Procedure-related complications were infrequent (8.7%; major complications: high grade AV block (2/231, 0.9%); minor complications: first degree AV block (6/231, 2.6%), reversible brachial plexus injury (2/231, 0.9%), and local hematomas or bruises (10/231, 4.3%)). The recurrence rate was 4.7% (10/212) during a follow-up period of 86 +/- 38 months (0.5-185 months).

CONCLUSIONS

The RF catheter ablation was a safe and effective method to manage children with paroxysmal and incessant tachycardia. The substrates of the arrhythmias differed between the pediatric and adult patients. However, the success rate of the ablation, complications, and recurrence during childhood were similar to those of adults.

Supraventricular tachyarrhythmias in Ebstein anomaly: management and outcome

OBJECTIVE

This study was undertaken to review the role of electrophysiology testing and to determine the early and late results of medical and surgical management of supraventricular tachyarrhythmias in Ebstein anomaly.

METHODS

We reviewed 130 patients between 1990 and 2001 with Ebstein anomaly and history of tachyarrhythmia with a median age of 25 years (mean age 27.5 years); 106 underwent electrophysiologic testing and 24 had documented atrial flutter or fibrillation. We excluded 21 patients: negative results of testing (n = 18), ventricular tachycardia (n = 2), and junctional tachycardia (n = 1). The remaining 109 patients had more than one mechanism: accessory pathway-mediated tachycardia (n = 49), atrioventricular nodal reentrant tachycardia (n = 10), and atrial flutter/fibrillation (n = 70).

RESULTS

Eighty-three patients underwent at least one arrhythmia procedure combined with surgery for Ebstein anomaly. Early mortality was 4.8%. Forty-one patients underwent surgical ablation of an accessory pathway without recurrent accessory pathway-mediated tachycardia at a mean follow-up of 48 months. Seven patients underwent surgical perinodal cryoablation for atrioventricular nodal reentrant tachycardia without recurrence at a mean follow-up of 57 months. Forty-eight patients underwent surgical intervention for atrial flutter or fibrillation (right-sided maze procedure, n = 38, and cryoablation of the atrial isthmus, n = 10). Freedom from recurrent atrial flutter or fibrillation was 75% at a mean follow-up of 34 months.

CONCLUSION

Concomitant arrhythmia procedures can be performed without increase in early mortality and should be added to Ebstein repairs for all patients who have supraventricular tachyarrhythmias. Surgical procedures for accessory pathway-mediated tachycardia and atrioventricular nodal reentrant tachycardia give excellent (100%) freedom from recurrence of those arrhythmias. Surgical intervention for atrial flutter/fibrillation yields freedom from late recurrence in 75% of cases.

Ebstein Anomaly Associated With Unusual Conduction Delay and Sick Sinus Syndrome-A Case Report-

A 64-year-old man was admitted to our hospital because of palpitation, dyspnea on effort, and facial edema. The echocardiographic diagnosis was Ebstein anomaly. Although the 12-lead electrocardiogram showed an atrial rate of 150 beats/min and no typical flutter wave, the electrophysiological study showed counterclockwise rotation of excitation along the tricuspid annulus. Because of sinus arrest and syncope, a permanent pacemaker was implanted, but the right atrium was not captured by electrical stimulation at 5 V/0.4 ms, except for the orifice of coronary sinus, and the intracardiac P wave was only 0.2 mV or less. This is a rare case of Ebstein anomaly characterized by unusually prolonged conduction in the atrium, the basis of which was global myocardial damage, including the ventricles.

The atrioventricular junctions in Ebstein malformation

OBJECTIVE

To review the anatomical structure of the right atrioventricular junction, including the specialised atrioventricular conduction system, in hearts with Ebstein's malformation, to identify potential substrates for the abnormalities in conduction.

METHODS

Five heart specimens representing the morphological spectrum of Ebstein malformation were examined grossly and histologically.

RESULTS

On the endocardial surface, the atrioventricular junction was marked by a faint line in two hearts, and by a small ridge in the other three. Analysis of the right parietal junction in four hearts revealed only two accessory muscular atrioventricular connections. A plane of fibrofatty tissue separated atrial from ventricular myocardium in the right parietal junction in all hearts. The compact atrioventricular node was closer to the coronary sinus than usual. Accessory nodoventricular connections were present in four hearts, while accessory fasciculo-ventricular connections were found in one. The right bundle branch was hypoplastic or absent in four hearts.

CONCLUSIONS

In this small series, the parietal atrioventricular junction was better developed than previously thought. Structural abnormalities of the atrioventricular conduction system, however, were present. These may account for some of the conduction abnormalities frequently observed with the Ebstein malformation.

Ebstein's Malformation

Ebstein's malformation of the tricuspid valve is a complex and heterogeneous disorder that has diverse hemodynamic and arrhythmic manifestations. Hemodynamic dysfunction is due to valvar regurgitation and decreased pulmonary blood flow, varying in severity from mild tricuspid insufficiency to severe dysplasia of the right ventricle without forward flow. Atrioventricular reentrant tachycardia and atrial tachyarrhythmias are commonly associated with Ebstein's malformation. Treatment ranges from conservative medical management to the ablation of pathways by catheterization to complex surgical repair or palliation. All patients with Ebstein's malformation should be followed on a regular basis by a cardiologist familiar with congenital heart disease. The frequency of evaluations should depend on the severity of the disease and the presence of arrhythmias. A specialist in electrophysiology should also follow those patients with complex arrhythmias.